112 TELEGONY AND REVERSION. 



In all probability the bair of the mane lengthened and 

 became more persistent as the hair of the body increased 

 in length and thickness. That the coat became thicker and 

 longer as the horse extended its range to mingle with the 

 reindeer and the other tundra fauna may be taken for 

 granted. While the long hairs of the mane and tail were 

 probably first acquired by natural selection, they may have 

 been retained and lengthened by artificial selection. The 

 Arab, probably evolved in a cold area, has retained the 

 long mane and tail; but the hairs, like those of the body 

 generally, are apt to be fine and silky. Occasionally, 

 according to Azara, horses were born in Paraguay with 

 hair like that on the head of a negro. In such horses the 

 mane and tail were short — they were, in fact, curiously 

 correlated to the hair on the body.* This further supports 

 the view that the long mane was acquired after the horse 

 left its ancestral home — perhaps long after it migrated 

 from the New into the Old World. 



There is in the horse family for some reason or other 

 always an intimate relation between the condition of the 

 mane and that of the tail. In the recent horse the mane 

 consists of long persistent hairs (sometimes the mane has 

 been over six feet in length), and the tail also from within 

 two or three inches of the base to the apex of the dock 

 consists of persistent hairs, those growing from the tip 

 being sometimes long enough to reach the ground. In the 

 zebra, as already stated, the mane, as a rule, consists of short, 

 upright, deciduous hairs, while the tail, though having long 

 persistent hairs at its tip, has deciduous (never very lono-) 

 hairs elsewhere. In zebra-horse hybrids the hair in the 

 mane, though sometimes double the length of that in the 

 zebra, seems to be shed annually' ; t and though there are 

 longish hairs up to the base of the tail, only the long hairs 

 springing from and near the tip persist. That the tail in 



* 'Animals and Plants,' vol. i, p. 56. 



t I have seen a zebra in which the maue, as in zebra hybrids and in the 

 ass of Somaliland, was long enough to fall slightly backwards and to one 

 side ; a further development might result in a horse-like niaue. 



